<!DOCTYPE html>
<html>
<body>
<ul aria-label="ul">
  <li aria-label="item1">Item 1</li>
  <li aria-label="item2">Item 2</li>
</ul>
</div>
<script>
  function go() {
    var item3 = document.createElement('li');
    item3.textContent = 'Item 3';
    item3.setAttribute('aria-label', 'item3');
    document.querySelector('ul').appendChild(item3);
  }
</script>
</body>
</html>
